Reward: | 4 quest points, 3100 coins

First things first, head to Ardougne and find Councilor Halgrive. He's usually hanging out near the Adventurer's or General store, so just keep an eye out for him.

Next, make your way to the Church located just north of where you found Councilor Halgrive. Speak with Doctor Orbon there. He'll offer you a protective suit for 100 gold coins. You'll definitely want to buy this, as it's crucial for protecting yourself from the plagued sheep later on.

Now, you'll need to travel directly north, past the edge of Ardougne, until you find a small building with a farmer in it. This is Farmer Brumty. Chat with him about the quest. He'll give you a pot of 'poisoned sheep feed' which you'll use on the plagued sheep once they're in the pen. While you're there, grab the 'cattle prod' from his house too – this is your tool for guiding the sheep.

This is the main part: you need to guide each of the four plagued sheep into the sheep pen using the 'cattle prod'. To do this, click on the cattle prod, then click on the sheep. This will teleport the sheep a short distance towards the pen. You then need to quickly run to the sheep and repeat the process before it wanders off again. Keep doing this, and the sheep will eventually be nudged into the pen.

The sheep aren't too far from the pen. The first two are southeast of it, pretty close to each other. The third is west of the pen, past a group of warriors. The last one is southwest of the pen, on the other side of the river. They're usually positioned so multiple players can work on them at once, which can make spotting them easier.

Once a sheep is safely inside the pen, use the 'poisoned sheep feed' on it. This will kill the sheep. After that, take its remains and use them on the furnace located inside the enclosed building. This ensures the sheep is dealt with properly.

Finally, head back to Councilor Halgrive in Ardougne, where you started. Tell him you've successfully killed all the sheep, and he'll give you your reward.